Typical current oilfield supply vessels are comprised of one single hull form, primarily composed of two rigidly joined elements (permanently attached to form a single vessel): an elevated pilothouse located near the bow of the vessel and a low cargo deck located behind the pilothouse and extending towards the stern of the vessel. The cargo deck of a typical oil field supply vessel has approximately 3 feet of freeboard (i.e. height of the sidewalls of the vessel above the waterline) when loaded. Thus, the design of the typical oil field supply vessel must locate the pilothouse forward, so that the pilothouse may shield the cargo on the low cargo deck from waves while the vessel is motoring. Due to this design configuration, the oilfield supply vessel must be maneuvered to back into mooring, so that the aft cargo deck can be easily offloaded (i.e. so that the cargo deck is located next to the oil platform for accessibility). This fact complicates mooring, however, since piloting a ship in reverse is more difficult than piloting forward. When mooring with oil platforms out at sea, standard operating procedure requires vessels to approach the oil platform downwind. Thus, a current oilfield supply vessel must maneuver backwards against the wind and seas as it approaches the oil platform. In this situation, the low cargo deck is unsheltered and takes on a great deal of green water (i.e. waves which sweep over the side of the vessel and onto the deck), endangering both cargo and crew. Furthermore, the oilfield supply vessel, which has a fairly high center of gravity due to the elevated superstructure of the pilothouse, would experience significant roll in these conditions, complicating mooring and offloading and increasing the risk for personnel on the cargo deck. The present invention addresses these and other concerns in an attempt to provide an improved means for supplying offshore oil platforms.